Council sewer comes in $1m under budget

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The most expensive single project the Palmerston North City Council has undertaken for several years has been achieved with $1 million to spare.

The Ashhurst to Palmerston North wastewater pipeline was expected to cost $5.59 million, but instead, came in just under $4.6m.

The savings were reported to the city council's audit and risk committee yesterday in line with a policy to measure outcomes for all projects worth more than $1m in a post project completion review.

The policy was introduced three years ago after budget blowouts at the Awapuni wastewater treatment plant and former landfill.

Wastewater assets engineer Phil Burt said the project involved laying more than 9 kilometres of pipeline to connect to the city network at Rosalie Tce, and building a pump station beside the existing sewage ponds.

The pumps work only at night so the wastewater from Ashhurst is run through the city's network while pressure on its capacity is otherwise low, arriving at the treatment plant before the usual morning peak.

The pipeline has also been designed to have capacity to cope with demand from future housing development at Whakarongo.

Although there were savings, the project did not meet its April deadline for completion, and was commissioned in August.

Most of the delay was attributed to finalising a price for the pump station, and waiting for a building inspection before its roof could be erected.

The extra couple of months of discharge happened when Manawatu River flows were high.

However, there is a possibility most of the $1m saved on the project will still have to be spent.

Horizons Regional Council has, since the project was first approved, raised the possibility that it might require the Ashhurst sewage ponds to be lined as part of a consent to continue using them. They are still used to collect and hold wastewater when the pumps are not working.

The estimated cost of that work could be about $750,000.

Cr Duncan McCann said while it was good that there were some savings for ratepayers from the project, the real winner was the Manawatu River. Piping Ashhurst's wastewater to the city's Totara Rd wastewater treatment plant meant it was treated to a higher standard before going into the river.

The discharge at Ashhurst had been stopped, and signs warning people not to swim near the discharge point had been made redundant.

Since the pipeline has been in use, it has not pumped the full volumes anticipated, prompting Cr Chris Teo-Sherrell to ask whether there had been a bad case of constipation in Ashhurst.